"MUTUAL DECOMPOSITION. 
277 
grammes of water, and each solution was kept in a state of Mutual de- 
ebullition for two hours on weight grammes of the sulphate of ™ nJe^nsotu- 
barytes. On analysing the' two residues it was discovered that ble neutral 
the subcarbonate of potash had produced 2*185 grammes of Salts ’ &C<> 
carbonate of barytes, while the sub-carbonate of soda had only 
yielded T833 grammes. This experiment was twice repeated, 
and the results did not sensibly differ. Thus two quantities 
of the sub-carbonate of soda, and of potash which contain the 
same chemical mass in their base, decompose the quantities of 
sulphate of barytes which are between them, nearly in the 
relation of 6 to 5. I shall soon return to the consideration of 
the consequences that may be deduced from this result. 
Since the soluble sub-carbonates can no longer produce the 
decomposition of an insoluble salt, when by the effect of this 
decomposition, the acid of this salt is found in a certain rela- 
tion with the acid or base of the sub-carbonate which is not 
decomposed, it becomes probable, that by artificially going 
beyond this limit ; inverse phenomena will be produced ; 
which, in fact, the following experiment has fully confirmed. 
Experiment. D. Seven grammes of chrystallised neutral sulphate 
of potash, and six grammes of ihe dry sub-carbonate of pot- 
ash, were dissolved in 250 grammes of water. This mixed 
solution was boiled with the sulphate of barytes, and after 
several hours of ebullition this latter salt. gave not the slightest 
indication of decomposition. The filtered liquid placed in the 
same circumstances with the carbonate of barites produced 
a considerable quantity of the sulphate of barytes $ and heated 
afresh by the carbonate of barytes, no decomposition took 
place, although it still contained sulphuric acid. 
In a similar experiment made with 15 grammes of the 
crystallised sulphate of soda and six grammes of the sub-car- 
bonate of soda, the sulphate of barytes was not attached, while 
the carbonate of barytes was converted into a sulphate, as far 
40*09 of carbonic acid and 59 91 of the base. I found by the same 
means that 100 parts of the dry sub-carbonate of potash contains : of 
#cid 3Q’70 ; of potash 69*3(f 
as 
